Answer:
option: C
Step-by-step explanation:
To determine the years when the mule deer population most likely experienced the greatest decrease in environmental resources based on the given graph, we need to identify the period with the steepest decline in population.
Looking at the graph, we can observe that the population starts decreasing sharply from around 1960 and continues to decline until around 1970. This period, from 1960 to 1970, represents the most significant decrease in the mule deer population.
Therefore, the correct answer is:
C. 1960-1970