What is the function of a pollen tube? to lead sperm cells into the ovary
to create more pollen
to create sperm cells
to lead egg cells to the sperm cells

The function of the pollen tube is to lead sperm cells into the ovary.

Explanation:

In angiosperms, the pollen tube is a structure formed when the pollen grain comes into contact with the stigma and germinates, producing a tubal extension that is related to the embryonic sac where the female gametophyte is found.

The function of the pollen tube is to conduct the male gametophyte —which is found in the pollen— to the embryonic sac, in order to come into contact with the oosphere and produce fertilization.

The other options are not correct because the pollen tube:

to lead sperm cells into the ovary .

Explanation: There needs to be a way for the sperm cells formed by the pollen's generative nucleus to reach the egg cells that are found in the ovary.