Answer:
We can see only a part of the graph, but let's try to answer this.
We will analyze each single option.
A) More prisoners escaped in 1942 than in any other year.
Here the brown line represents the prisoners that escaped. If this statement is true, then the highest point of the brown line in the graph should be on the 1942 value of the x-axis. But we can see that it is not the case, the highest point of the brown line is at 1934, then the statement is false.
B) Staling stoped sending prisioners to the Gulags after 1946.
We can see that the blue line (the one that represents the number of prisioners) increases in 1946, so no, this is false.
C) The german invasion of the soviet union heavily disrupted its gulag prision system.
The german invasion occurs in 1941, in the graph we can see that in 1941 the blue line (the one that counts the total number of prisioners) starts decreasing, until it reaches its local minimum between the years 1944 and 1946.
Then yes, we can see that the german invasion affected the gulag prision system.
D) Prision escapes were a major problem in the soviet union.
In the graph we can see that the brown line is pretty low, it is only noticeable until 1938, after that point, the brown line is near the bottom, then no, prisioner escapes were not a major problem.
The correct option is C.