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: