Question

part a
corals need 10 to 15 years to recover from a bleaching event. the graph shows
the frequency of the number of years between severe bleaching events split
between 1980 - 1999 and 2000 - 2016.
based on the data, which statement describes a conclusion about coral bleaching
when comparing years 1980 - 1999 to 2000 - 2016?
a the frequency of both severe and moderate bleaching events remains
constant.
b the time between severe bleaching events remains constant and
long enough for full recovery.
c the time between severe bleaching events decreases to about half the time
needed for recovery.
d the frequency of severe bleaching events decreases, while the frequency of
moderate bleaching events increases.

Explanation:

• For option A: The bar - heights (frequencies) for different time - intervals are not the same for 1980 - 1999 and 2000 - 2016, so the frequency of bleaching events is not constant.
• For option B: Corals need 10 - 15 years to recover. In 2000 - 2016, there are more bars in the 1 - 6 year intervals (which is less than the recovery time), so the time is not long enough for full recovery.
• For option C: Corals need 10 - 15 years to recover. In 2000 - 2016, there is a significant increase in the number of bleaching events in the 1 - 6 year intervals (e.g., 1 - 3 and 4 - 6 years). 1 - 6 years is about half of the 10 - 15 year recovery period.
• For option D: The graph shows the time between bleaching events, not the severity (severe or moderate) of the bleaching events.

Answer:

C. The time between severe bleaching events decreases to about half the time needed for recovery.