Statement-1"C-O bond length is shorter in an ester as compared with an anhydride.
Statement-2:A degree of cross conjugation exist in the anhydride which decreases the delocalisation to each carbonyl oxygen.

Options

A. Statement-1 is True, Statement-2 is True, Statement-2 is a correct explanation for Statement-1
B. Statement-1 is True, Statement-2 is True, Statement-2 is NOT a correct explanation for Statement-1
C. Statement-1 is True, Statement-2 is False.
D. Statement-1 is False, Statement-2 is True.

Explanation

To solve the problem, we need to analyze both statements regarding the bond lengths in esters and anhydrides and the concept of cross conjugation.

### Step-by-Step Solution:

1. **Understanding the Structures**:
- An ester has the general structure: R-C(=O)-O-R'.
- An anhydride has the structure: R-C(=O)-O-C(=O)-R'.

2. **Analyzing the C-O Bond Length in Esters**:
- In esters, the C-O bond has some double bond character due to resonance. The resonance structure can be represented as R-C(=O)O⁻, where the lone pair on the oxygen can participate in resonance with the carbonyl group.
- This resonance leads to a shorter C-O bond length compared to a single bond.

3. **Analyzing the C-O Bond Length in Anhydrides**:
- In anhydrides, there is a degree of cross conjugation. The resonance structures can be represented as R-C(=O)O⁻ and R'-C(=O)⁺.
- The presence of multiple carbonyl groups allows for resonance, but not all pi bonds participate in resonance effectively due to the cross conjugation effect. This results in a longer C-O bond length compared to esters.

4. **Cross Conjugation**:
- Cross conjugation occurs when there are multiple pi bonds, but only some of them interact. In the case of anhydrides, the presence of two carbonyl groups means that while there are three pi bonds, only two effectively participate in resonance. This reduces the delocalization of electrons over the carbonyl oxygens.

5. **Conclusion**:
- Statement 1 is true: The C-O bond length is shorter in an ester compared to an anhydride.
- Statement 2 is also true: The degree of cross conjugation in anhydrides decreases the delocalization to each carbonyl oxygen, leading to longer C-O bond lengths.

Thus, both statements are true, and Statement 2 correctly explains Statement 1.

### Final Answer:
Both statements are true, and Statement 2 is the correct explanation for Statement 1.