The cardiac electrical impulse normally begins spontaneously in the sa node because
a. of the superior location of the sa node in the right atrium.
b. the sa node is the only area of the heart capable of spontaneous depolarization.
c. of the rich sympathetic innervation of the sa node.
d. this area depolarizes more rapidly than any other portion of the conduction system.
e. of action potentials from the cardioregulatory cente

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 d. none of the above