Answer:
A. I
Step-by-step explanation:
sin is defined as y and cos is defined as x.
That means only QI can have sin > 0 and cos > 0
QII has sin > 0 but cos < 0 because cos = x and x is in negative side.
QIII has both sin and cos < 0 because sin and cos are in negative side.
QIV has sin < 0 but cos > 0 because cos is in positive x.
Therefore, sin > 0 and cos > 0 at same time in QI
