It's D.diploid
<span>in the life cycle of plants with alternating generations) the asexual and usually diploid phase, producing spores from which the gametophyte arises. It is the dominant form in vascular plants, e.g., the frond of a fern.</span>
1.) is circulatory system. An easy way to remember this is, blood circulates throughout the body, CIRCULatory.
2.) Circulatory; resspiratory.
HOpe i could help and this got to you in time! :)