The correct option is C 52 and 78
From the table, we observe that
Height of the tree for 2 months = 26 inches
Hence, height for 1 month = 262 = 13 inches
For 4 months,
Height = 4(13) = 52 inches
For 6 months,
Height = 6(13) = 78 inches
Hence, the missing values in the table are 52 and 78