Which Context to use with MediaPlayer.create() in android?

Which Context to use with MediaPlayer.create() in android?

Which context i should use with MediaPlayer.create() ? I am using
Activity.this with all my MediaPlayer objects.But i think it is giving me
null pointer exception. Can context be a reason for force close in android
or anything else ?
Here "com.bhavin.panara.kbc" is package name. And 108th line is
mediaplayer.start().
Here is my log cat report.
java.lang.RuntimeException: Unable to start activity
ComponentInfo{com.bhavin.panara.kbc/com.bhavin.panara.kbc.PlayScreen}:
java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1999)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2026)
at android.app.ActivityThread.access$600(ActivityThread.java:127)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1174)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4506)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at
com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:809)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:576)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at com.bhavin.panara.kbc.PlayScreen.onCreate(PlayScreen.java:108)
at android.app.Activity.performCreate(Activity.java:4479)
at
android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1050)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1963)
... 11 more