713. the number of points in the rectangle (c, y)| -10 10 and -3y<31 bieao0sp which lie on the curve y4 = t + sin c and at which the tangent to the curve is par

713. The number of points in the rectangle (c, y)| -10 10 and -3y<31 bieao0sp which lie on the curve y4 = t + sin c and at which the tangent to the curve is parallel to the t-axis, is (A) 0: (B) 2; (C) 4; (D) 8.