In response to seasonal changes in temperature, many organisms must alter the composition of their plasma membranes to maintain the proper degree of fluidity. Which change in the fatty acids of phospholipids would be most effective in maintaining membrane fluidity in a colder environment?

A. an increase in phospholipid fatty acid side chain length and an increase in side chain saturationB. a decrease in phospholipid fatty acid side chain length and an increase in side chain saturationC. a decrease in phospholipid fatty acid side chain length and a decrease in side chain saturationD. an increase in phospholipid fatty acid side chain length and a decrease in side chain saturation