Stress is a ______ quantity.
According to terms in Physics,
Scalar is a quantity having only magnitude.
A vector is a quantity that has magnitude and direction both.
Tensor is a quantity having magnitude, direction, and plane too.
Stress is a tensor as it obeys the coordinate transformation law. Stresses are not vectors because they do not combine according to the parallelogram law of addition. Instead, stresses are much more complex quantities than the vectors and are called tensors. Stress is a second-order tensor. Also, it has a dimension too.
Thus option C is correct.