Define frequency:

the distance from the rest position to a crest or a trough; the more energy, the greater the amplitude

a repeated back-and-forth or up-and-down motion.

the part of a longitudinal wave where the particles are far apart

the number of waves that pass a set point in a certain amount of time

the number of waves that pass a set point in a certain amount of time

Explanation:

Frequency (f) is the number of cycles a wave can complete in one second. The standard unit of frequency is Hertz (Hz).

Mathematically, frequency of a wave is inversely proportional to its period (T)

i.e F = 1/T

answer: angiosperms

dicots

angiosperms are highly evolved plants, they produce seeds which are enclosed within in a carple. these are the largest group of plants on earth. they include trees, shrubs, herbs and small flowering plants. angiosperms exhibit a flowering stage in their life cycle. the flower serves the function of reproduction and fruit formation in majority of angiosperms. dicot is the term used to describe flowering plants that have two seed leaves. dicots are plants which develop seeds which split into two parts called cotyledons. each cotyledon contains one embryo.

here, a small purple flower development indicates that the plant belongs to angiosperms and having two embryonic leaves indicates it belongs to dicots.  

the answer is b.) hydrogen bonds between bases.