Which artery carries deoxygenated blood instead of oxygenated blood?

Select the mismatched pair from the following.

Which of the following statements about the human heart is correct?

When cardiac muscle cells are damaged by a heart attack,they are usually replaced by

Cardiac muscles contract:

When the heart of a frog is removed from the body,it continues to beat for some time. Select the correct statement$(s)$ from the following:
$(i)$ The frog is a cold-blooded animal.
$(ii)$ The frog does not have a heart-based circulatory system.
$(iii)$ The heart has myogenic properties.
$(iv)$ The heart is self-excitable.