The number sentence that is true is 5/6 ÷ 1/5 = 4 1/6 which is option D
5/6 ÷ 1/5 can be written as
changing the division sign to multiplication, which we take the reciprocal of the fraction after the division sign
which becomes
5/6 x 5/1 = 25/6
expressing 25/6 as a mixed fraction you have 4 1/6
which is the only true mathematical sentence amongst the given expressions.