Since four is the first digit, the second or third digits cannot be eight as ‘e’ comes before ‘f’ and the digits are in alphabetical order. It can also not be five as ‘fo’ in four comes after ‘fi’ in five.
They can neither be four nor zero as all four digits must be different.
We can form an equation to match the information provided to us.
We know 4 has four letters
We know 0 has four letters
Let the 2nd digit be S
Le the 3rd digit be T
4 + 0 + S + T = 8 + Number of letters in S + Number of letters in T
S + T = 4 + Number of letters in S + Number of letters in T
By placing in different digits, we get the answer to be 9 and 2.
Total number of letters in 9 and 2 = 4 + 3 = 7
So the answer is B