Error running 'app': Default Activity not found

[marvelstardom]

Please I need your help. I keep getting this whenever I try to run the app. How can I fix this? Thanks.

This is my manifest code.

<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.uber">

<!--
     The ACCESS_COARSE/FINE_LOCATION permissions are not required to use
     Google Maps Android API v2, but you must specify either coarse or fine
     location permissions for the 'MyLocation' functionality.
-->
<!--<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />-->
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.INTERNET" />

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:roundIcon="@mipmap/ic_launcher_round"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">

    <activity android:name=".MainActivity">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <activity android:name=".CustomerLoginActivity" />
    <activity android:name=".MapActivity" />
    <activity android:name=".DriverLoginActivity" />

    <!--<activity-->
        <!--android:name="com.example.android.GizmosActivity"-->
        <!--android:label="@string/title_gizmos" >-->
        <!--<intent-filter android:label="@string/filter_title_viewgizmos">-->
            <!--<action android:name="android.intent.action.VIEW" />-->
            <!--<category android:name="android.intent.category.DEFAULT" />-->
            <!--<category android:name="android.intent.category.BROWSABLE" />-->
            <!--&lt;!&ndash; Accepts URIs that begin with "http://www.example.com/gizmos” &ndash;&gt;-->
            <!--<data android:scheme="http"-->
                <!--android:host="www.example.com"-->
                <!--android:pathPrefix="/gizmos" />-->
            <!--&lt;!&ndash; note that the leading "/" is required for pathPrefix&ndash;&gt;-->
            <!--&lt;!&ndash; Accepts URIs that begin with "example://gizmos” &ndash;&gt;-->
            <!--<data android:scheme="example"-->
                <!--android:host="gizmos" />-->

        <!--</intent-filter>-->
    <!--</activity>-->

    <!--
         The API key for Google Maps-based APIs is defined as a string resource.
         (See the file "res/values/google_maps_api.xml").
         Note that the API key is linked to the encryption key used to sign the APK.
         You need a different API key for each encryption key, including the release key that is used to sign the APK for publishing.
         You can define the keys for the debug and release targets in src/debug/ and src/release/.
    -->
    <meta-data
        android:name="com.google.android.geo.API_KEY"
        android:value="@string/google_maps_key" />

    <activity
        android:name=".DriverMapActivity"
        android:label="@string/title_activity_driver_map"></activity>

</application>