How many months will the NAS run out of available storage space?

A technician performs monthly backups on a file server to a NAS device that can hold 1TB of data. The size of the monthly backups has been as follows:
Month 1 = 50GB
Month 2 = 65GB
Month 3 = 80GB
Starting with Month 1, based on the current rate of growth, in how many months will the NAS run out of available storage space?
A. 4
B. 5
C. 9
D. 11