Spanish question

Which of the following is the first-person singular (yo) form of the verb "to think" in present tense? a. pienso b. penso c. piensa d. pensamos

Brainliest.if you answer number 2, 3,and 4. ill give brainliest. dont answer just for brainliest.picture is above.

What is the answer to cuando as el cumpleanos de sergio