Answer:
a.Smooth.
Explanation:
Smooth muscle -
It is a type of muscle tissue , which is present in many vessels and pressure .
it is composed of cells of the sheets of the smooth muscle cells .
The cells of smooth muscle have fibers of myosin and actin .
The function of smooth muscle is as follows -
It is involved in the digestive track and blood vessels .
Hence , from the given information , the correct answer is smooth vessel .