The answer for you is D the last one

C and D are both possible.

But we have no idea which one is correct based on the given illustration, because you didn't give the illustration.

Density.

It's a measure of mass per unit volume (density measures how much "stuff" there is in a particular space).

**Explanation:**

As the given rod is attached to rigid supports as a result, the deformation occurring due to the change in temperature will cause stress in the rod.

Let us assume that P is the compressive force in the rod due to change in temperature.

So,

=

=

Now, we will calculate the actual change in temperature as follows.

This means that the actual change in temperature is more than required for yielding.

**(a)** Formula to calculate yielding stress is as follows.

=

=

=

Hence, **stress in the bar when temperature is raised to **** is ****.**

**(b) ** Now, we will calculate the residual stress as follows.

= 15.837 ksi

Therefore, **stress in the bar when the temperature has returned to **** is 15.837 ksi.**