Question

I am tired as; since 6 o’clock in the morning.
A) I was studying
B) I have been studying
C) I had been studying
D) No correction required

Answer 1

B is the right answer in my opinion

Answer 2

$\huge\boxed{\texttt{\fcolorbox{purple}{pink}{Heya! }}}$

I am tired as I have been studying since 6 o'clock in the morning .