Correct Answer  Option 2 : sin α
Concept:
The table below shows the sign of trigonometric ratios in different quadrants:
T – Ratio’s

Quadrant I

Quadrant II

Quadrant III

Quadrant IV

Sin

+

+





Cos

+





+

Cosec

+

+





Sec

+





+

Tan

+



+



Cot

+



+



Calculation:
(π + θ) lies in 3rd quadrant
As we know sin θ gives negative value in 3rd quadrant
Therefore, sin (π + α) = sin α