Quiz</h1>
        <div class="question">
            <p>Which of the following is NOT an operation that preserves the convexity of sets?</p>
            <ul class="options">
                <li><label><input type="radio" name="q0" value="0"> a) Scaling a convex set by a real number.</label></li>
                <li><label><input type="radio" name="q0" value="1"> b) Translating a convex set by a vector.</label></li>
                <li><label><input type="radio" name="q0" value="2"> c) Taking the union of tw