I can do the first question for you.
a. List the years in order of increasing ring width.
1930, 1910, 1900, 1920, 1940
b. Which year was hottest?How do you know?
The hottest is 1930 Wider rings for warm periods, trees that depend heavily on moisture during the growing season will have wider rings during rainy periods and narrower rings during dry periods.
c. Which year was the coldest? How do you know?
The coldest year is 1940 because trees that depend heavily on temperature in the growing season will have narrow rings during cold periods.