Ans.
Steroids are defined as active organic bio-molecules, having four rings with a specific molecular configuration. Steroids play role in two major functions: as hormones or signaling molecules and as structural components of plasma membrane.
Examples of steroid hormones are estrogen, progesterone, and cortisol. Thus, the correct answer is 'option b). they serve as chemical messengers.'
Igneous rocks are rocks that form from magma, or they crystallize directly from a liquid.
Metamorphic rocks<span> form from the heating and pressurization of rock that is already solid.</span>
I would say D) all of the above.
