To solve this question, we need to evaluate the different bond representations provided: A \(\rightarrow\) B, A\(^+\)B\(^-\), and A\(^-\)B\(^+\), and determine which has the least contribution to the actual molecular structure when element A is more electronegative than element B.
- A \(\rightarrow\) B: This structure represents a coordinate bond where electron pair is donated by A to B. Since A is more electronegative, it is plausible but not the dominant structure.
- A\(^+\)B\(^-\): In this ionic representation, A has a positive charge, and B has a negative charge. However, since A is more electronegative, it will not easily lose electrons to become positively charged. Hence, this structure is unrealistic and contributes the least.
- A\(^-\)B\(^+\): This structure implies A having a negative charge and B a positive charge. Being more electronegative, A holds on to electrons more tightly, making this structure more reasonable than II.
Considering the nature of electronegativity, the least probable structure when A is more electronegative than B is A^{+}B^{-} (II), where the more electronegative element (A) is assigned a positive charge.
Hence, the correct option is II.