Let a and 7 be two vectors in three dimension. Let a = a y b. Which of the following is true? O a. c is parallel to a, but not parallel to b. O b. None of the other answers is correct. O c. c is parallel to both a and b. O d. c is perpendicular to a, but not perpendicular to i. O' e. c is parallel to b, but not parallel to a. O f. c is perpendicular to both a and b. O g. c is perpendicular to 7, but not perpendicular to a