Living in the ocean surrounded by water, most marine mollusks have which type of reproduction?
a. external fertilization
b. internal fertilization
c. self-fertilization
d. hermaphroditism

b. Internal fertilization

Explanation:

Reproduction of molluscs is exclusively sexual. There are some hermaphrodite species, however, most are dioecious (separate sexes). Fertilization is usually internal, but may rarely be external. An example is the garden snail, which is monoecious. In copulation, two individuals of different sexes approach and touch their genital pores, fertilizing each other.

Development can be direct or indirect, the latter being the most common; The most well-known larval stages are the trochophor, similar to marine annelids.

well

explanation:

the relative atomic mass of an element is the mass of one atom of that element, relative to 1/12th of the mass of a  1212c atom. to convert to an absolute mass in kg, it is necessary to multiply by  1.661×10−271.661×10−27.

the relative atomic mass is roughly equal to the number of neutrons, plus the number of protons, in the nucleus of the atom.

for elements with more than one stable isotope (different types of nucleus with different numbers of neutrons but the same number of protons), the quoted mass is usually the average mass, weighted by the relative abundance of the different isotopes.