Which of the following mechanism shows the correct curve arrow of the reaction of the enolate ion from ethyl acetate with ethyl acetate in the Claisen condensation?

• A. <img alt="Mechanism shows curve arrow of reaction of enolate ion from ethyl acetate - option a" class="alignnone size-full wp-image-281987" height="84" src="https://www.sanfoundry.com/wp-content/uploads/2018/08/organic-chemistry-questions-answers-aptitude-test-q10a.png" width="189"/>
• B. <img alt="Mechanism shows curve arrow of reaction of enolate ion from ethyl acetate - option b" class="alignnone size-full wp-image-281986" height="94" src="https://www.sanfoundry.com/wp-content/uploads/2018/08/organic-chemistry-questions-answers-aptitude-test-q10b.png" width="231"/>
• C. <img alt="Mechanism shows curve arrow of reaction of enolate ion from ethyl acetate - option c" class="alignnone size-full wp-image-281985" height="82" src="https://www.sanfoundry.com/wp-content/uploads/2018/08/organic-chemistry-questions-answers-aptitude-test-q10c.png" width="197"/>
• D. <img alt="Mechanism shows curve arrow of reaction of enolate ion from ethyl acetate - option d" class="alignnone size-full wp-image-281984" height="92" src="https://www.sanfoundry.com/wp-content/uploads/2018/08/organic-chemistry-questions-answers-aptitude-test-q10d.png" width="218"/>