Resonance effect is not observed in

Which one among the following resonating structures is not correct?

The correct order of $C=O$ bond length in ethyl propanoate $(I)$, ethyl propenoate $(II)$ and ethenyl propanoate $(III)$ is

Which of the following is not a valid resonating structure of the others?

Given below are two statements.
Statement $I :$ The dipole moment of $CH_3-CH=C(CH_3)-CH=O$ is greater than $CH_3-CH_2-CH_2-CH=O$.
Statement $II :$ $C_1-C_2$ bond length of $CH_3-CH=CH-CH=O$ is greater than $C_1-C_2$ bond length of $CH_3-CH_2-CH_2-CH=O$.
In the light of the above statements,choose the correct answer from the options given below $:$

Which one of the following compounds does not exhibit resonance?