Assertion (A): Integer class can be used in the program without calling a package.

Reason (R): It belongs to the default package java.lang.

1. Both Assertion (A) and Reason (R) are true and Reason (R) is a correct explanation of Assertion (A)
2. Both Assertion (A) and Reason (R) are true and Reason (R) is not a correct explanation of Assertion(A)
3. Assertion (A) is true and Reason (R) is false
4. Assertion (A) is false and Reason (R) is true

What is the method to check whether a character is a letter or digit?

1. isDigit(char)
2. isLetterOrDigit()
3. isLetterOrDigit(char)
4. isLETTERorDIGIT(char)

State the data type and value of res after the following is executed:

char ch = '9';
res= Character.isDigit(ch);