What is the uppermost layer of atmosphere called

Which was not a country that massively built up its navy in the early 1900s? germany china united statesbritain

What are the answers for the following questions?

Compare the quantity in column a with the quantity in column b. pa p a is tangent to the circle at a. column a column b ap a p ax a x question 4 options: the two quantities are equal. the quantity in column a is greater. the relationship cannot be determined from the information given. the quantity in column b is greater.