Correct Option: A

Characteristics of smooth muscle fibres.
• cells range from 5 to 10 µm in diameter and 30 to 200 µm in length
• spindle-shaped
• single, centrally located nucleus
• smooth muscle tissue occuring within almost every organ, forming sheets, bundles or sheaths around other tissues.
Smooth muscle differs from both skeletal and cardiac muscle tissues in structure and function. Sarcomeres or myofibrils are not present - therefore not striated, ie. smooth.