The correct option is C 5
To find the maximum capacity of a jug that can measure the water of the two buckets an exact number of times, we have to find the HCF of 15 and 35.
Factors of 15 = 1, 3, 5, 15
Factors of 35 = 1, 5, 7, 35
Highest common factor of 15 and 35 = 5
Therefore, a 5 litre jug can be used to measure 15 and 35 litres of water an exact number of times.