The diagrams illustrate skeletal formulas for some isomers of $\mathrm{C_6H_{12}O}$. Which statement is true?
- A1 and 3 are chain isomers of each other and positional isomers of each other.
- B2 and 3 are functional group isomers of each other and both have a chiral centre.
- C1 and 4 are functional group isomers of each other and both have a chiral centre.
- D2 and 4 are positional isomers of each other and functional group isomers of each other.