62.馬拉松選手剛跑完全程後突然暈倒，其原因以下列何者最常見？
(A)心律不整
(B)血壓降低
(C)血液中鈉離子濃度太低
(D)血糖太低

After exercise, without the muscular activity to increase venous return, cardiac filling may decrease dramatically because of the reduction in left ventricular end-diastolic volume and stroke volume. Circulating catecholamines and forceful ventricular contractions against a diminished ventricular volume are postulated to stimulate ventricular mechanoreceptors excessively. Afferent vagal C-fibers subsequently transmit these signals to the central nervous system with efferent reflexes, resulting in vasodilation and bradycardia, and leading to hypotension and syncope.

(https://www.aafp.org/afp/1999/1101/p2001.html)