The part of a desired plant inserted into rootstock during grafting is called the

The answer is; scion

Successful grafting ensures a proper vascular connection between the scion and rootstock tissue, therefore, plants lacking a vascular cambium, such as monocots, cannot normally be grafted.   Grafting, a type of asexual reproduction, is particularly important in the horticultural industry. The two plants being grafted must be close genetically for a successful graft union.

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.

the answer is c. it will give up it's valence electron to the other atom.