The level curves of the surface z=x+y2 are circles in the xy-plane centered at the origin. Without computing the gradient, what is the direction of the gradient at (1.3) and (2,1) (determined up to a scalar multiple)? Determine the direction of the gradient at (1,3). Choose the correct answer below. OA. (-3,1) OC. (1,3) OB. (1.-3) OD. (3.1) OF. (3,-1) 'O E. (-1,3) Determine the direction of the gradient at (2,1). Choose the correct answer below. OB. (1,-2) OA. (2-1) OC. (-1,2) O E. (1.2) OD. (2.1) OF. (-2,1)