A) am
B) is
C) are
D) be
Correct Answer: A) am
Explanation:
The subject “I” always takes the verb “am” in the present tense.
So,
I am happy. ✔️
Other options:
is – used with he, she, it
are – used with you, we, they
be – base form, not used directly with “I” in this sentence
Therefore, the correct sentence is: I am happy.