Which is a point mutation?
a. frameshift
b. insertion
c. deletion
d. missense

Missense mutation: changes the codon causing the amino acid change. If the properties of amino acid (polarity, charge etc.) remain the same, then the mutation is called conservative, in which case it may not affect the protein's function. Otherwise, the mutation is called non-conservative, and it can lead to the loss of protein function and result in disease.

Explanation:

where is the option.let me know

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.