Raft foundation are generally preferred to when the area required for individual footing, is more than

<p> </p> <strong><a><span><span>A.</span></span></a></strong> <strong>25% to total area</strong> <strong><a><span><span>B.</span></span></a></strong> <strong>30% of total area</strong> <strong><a><span><span>C.</span></span></a></strong> <strong>40% to total area</strong> <strong><a><span><span>D.</span></span></a></strong> <strong>50% of total area.</strong> <p> </p>