If you saw / the amount of Samosas / he consumed at breakfast this morning,/ you would understand why he is so over-weight.

Answer: Option B

Replace, amount → number.

Difference Between Number and Amount
The confusion between amount and number is common but can be easily overcome. They are not interchangable - their use relates to countable and uncountable nouns.

Use of Amount
Use amount is with uncountable nouns and abstract nouns:
amount of time
amount of snow
amount of noise
amount of love (abstract noun)
amount of pride (abstract noun)

Use of Number
Use number with countable nouns (things that can be counted):
number of cars
number of chairs
number of houses
number of topics