Answer:
e. it expands in horizontal direction
Step-by-step explanation:
By the law of thermal expansion of metals we know that when a metal is heated it expands due to the thermal properties of its molecules.
Mathematically this expansion in its length is given by:

where:
original length of the metallic piece
coefficient of linear expansion
rise in temperature
- Here, in the given question we have a bimetallic strip with one end attached to the wall rigidly so that it is in horizontal orientation.
- Upon heating the strip gains the temperature and expands horizontally along the length because it is fixed to the wall only from one end.