Plzz help Which describes a promoter?

a. the first part of an operon that regulates where, when, and to what level a gene is
expressed

b. the part of an operon that, if attached by a repressor protein, suppresses the
expression of a gene

c. a cluster of genes that are expressed or repressed as a group

d. an enzyme that helps DNA unzip prior to transcription

answer; i believe the answer is hydraulic action;

what are the options

a. seed plant structure. 1. the three main plant organs are roots, stems, and leaves. a fourth kind of tissue, meristematic tissue, is responsible for plant growth. meristematic tissue is the only plant tissue that produces new cells by mitosis. plants can lose water out of their leaves as they exchange gases with the air

explanation: