Identify the following compounds. (Relative integrals are given from left to right across the spectrum.)
a. The 1H NMR spectrum of a compound with molecular formula C4H10O2 has two singlets with an area ratio of 2 : 3.
b. The 1H NMR spectrum of a compound with molecular formula C6H10O2 has two singlets with an area ratio of 2 : 3.
c. The 1H NMR spectrum of a compound with molecular formula C8H6O2 has two singlets with an area ratio of 1 : 2.