Susan suffered from a heart attack. when the doctors tested the heart muscle, they found that she had an increased ratio of lactic acid to pyruvic acid in her heart. what does this say about the availability of oxygen in her heart muscle cells

Because of reduced blood supply

Explanation:

The normal heart has low pyruvic acid to lactic acid ratio which shows the heart is working properly and has no problem in it.

The heart with low pyruvic acid to lactic acid ratio shows that it has some respiratory problem and does not have adequate oxygen supply.

Even the person having  very low  pyruvic acid to lactic acid ratio shows respiratory problem.

an important event in the author’s life

Option C.

Explanation:

The passage given in the question has been taken from "Ellis island" which has been written by Barbara Davis Pyle. It is about an important event in the life of the author which speaks about when the author along with his parents crossed the harbor of city and entered the United States of America.

This was the event of starting a new life by the author with his family. This it was one of the major and happy events.