In how many of the following reactions, aldehyde is formed as a product? <img class="img-fluid question-image" alt="Question" src="https://cdn.tardigrade.in/q/nta/c-wsmeqnngsnaeyeyh.jpg" /> <img class="img-fluid question-image" alt="Question" src="https://cdn.tardigrade.in/q/nta/c-wsmeqnngsnaelh97.jpg" /> <img class="img-fluid question-image" alt="Question" src="https://cdn.tardigrade.in/q/nta/c-wsmeqnngsnaezmzx.jpg" /> <img class="img-fluid question-image" alt="Question" src="https://cdn.tardigrade.in/q/nta/c-wsmeqnngsnae6byw.jpg" />