Assertion - The opening and closing of the pore is a function of the guard cells. Reason - Stomatal pores are the site for the exchange of gases by diffusion.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.