Question

What prevents backflow of blood inside the heart during contraction ?

(a) Valves in heart
(b) Thick muscular walls of ventricles
(c) Thin walls of atria
(d) All of the above

Pls follow me...​

Answer 1

Answer:

d)ALL OF THESE

Explanation:

hope it will help you

Answer 2

Answer:

_______ Option A _______