A nurse is assessing the dorsalis pedis pulse of an 88 yr old client...(I have the answer but PLEASE EXPLAIN)

A nurse is assessing the dorsalis pedis pulse of an 88 year old client. She notes the feet to be cool and assesses weak pedal pulses. The nurse's next action would be to

a)assess the popliteal and femoral pulses
b)assess a 1 minute apical pulse
c)notify the physician STAT
d)apply a warm pack and re-asses in 20 min

The answer is A. Please explain why that is the answer. Also my prof said the apical pulse isnt going to tell you much... why is that so?

Palpation of the pulses is an important part of the assessment of the arterial blood supply of the lower limb. In clinical practice, this assessment may give clues about a compromised circulation, (for example ntermittent claudication, a condition of the leg caused by blockage of the arteries.) In this condition pain in the lower limbs develops during walking/ is relieved by rest. A patient with intermittent claudication may have weak or absent pulses in the lower limb. The limb may be cold to the touch and cyanosed (blue) and there may be local hair loss.

So,it is important to palpate the dorsalis pedis and posterior tibial pulses in both limbs and, if absent, the popliteal and femoral pulses. You would be going upward, to detect where the blockage is occuring (at each point where there is a branch off). Can catch emboli before they cause major damage locally or go to the lungs.

Also, the apical pulse isn't detected in an artery, and is unilateral (no comparison), making it less useful in clinical practice (If it is reduced so what? Doesn't tell you where the blockage might be). Could also be affected by heartbeat irregularities, since you are hearing the actual heartbeat.