TextWatcher interface defines three callbacks: beforeTextChanged(), onTextChanged(), and afterTextChanged(). Which callbacks must be implemented to avoid a syntax error? a. onTextChanged() only b. afterTextChanged() only c. beforeTextChanged() and onTextChanged() d. All three callbacks a. an action taken when a user interacts with a widget b. a warning dialog displayed when further information is needed c. a timestamp indicating the start of an action d. a change in the device orientation Which of the following is NOT a valid android:inputType attribute value for an EditText widget? a. textEmailAddress b. number c. textPassword d. textSingleLine What does the match_parent constant do in a layout file? a. Gives the maximum amount of space allowed by the parent ViewGroup to display content b. Gives just enough space to display content c. Gives the minimum amount of space allowed by the parent ViewGroup to display content d. Gives just enough space to display content plus a 5 px border What class provides global information about an application or app component? a. An anonymous inner class b. Context class c. Button class d. Activity class