What is the effect of the presence of double bonds in plant lipids? A) the double bonds do not affect the properties of plant lipids
B)the double bonds cause plant lipids to freeze more quickly
C)the tails of plant lipids cannot pack as tightly together as animal ones

Option C.

C)the tails of plant lipids cannot pack as tightly together as animal ones

Explanation:

The tails of plant lipids cannot pack as tightly together as animal ones because the double bond in plant lipids make the hydrocarbon chains to bend making them no to pack tightly together which cause a reduction in van der Waals interaction between the fatty acids. The length of the double bond also affect the melting point of fatty acids . If the hydrocarbon chain is long, melting point will be high .

i'm thinking (a) to keep sand in place; ////////////

explanation: a sand fence or sandbreak, like a snow fence, is used to force windblown, drifting sand to accumulate in a desired place. sand fences are employed to control erosion, sand dune stabilization, keep sand off roadways, and to recruit new material in desert areas.