Yes your choices of B C D are right
In 1871, a Russian Chemist, Dimitri Mendeleev, gave a useful scheme for classification of elements. He presented the first regular periodic table in which elements of similar chemical properties were arranged in eight vertical columns called groups. The horizontal rows of table were called periods. He arranged elements in ascending order of their atomic masses and found that elements having similar chemical properties appeared at regular intervals. This observation was called Periodic Law.
Explanation:
Let the mass of isoamyl acetate be 100g.
Moles of Carbon = 60.58/12 = 5.048mol
Moles of Hydrogen = 7.07/1 = 7.07mol
Moles of Oxygen = 32.28/16 = 2.018mol
Mole Ratio of C : H : O
= 5.048 : 7.07 : 2.018
= 5 : 7 : 2.
Hence the empirical formula of isoamyl acetate is C5H7O2.