Write the next sentence in this paragraph:

How to do abdominal crunches with angled heels
Lie down facing the ceiling with your knees bent and your shoulders, hips, and feet aligned.
Flatten your back and clench your abs, clasping your hands together behind your head.
Raise your toes up so that your heels press into the ground.

Choose your answer from: (i) This should work your upper thigh muscles; if you do not feel the effort there, try pressing a little harder. Bring your head and shoulders up towards your hips in a typical crunch motion. (ii) Slowly lean over until your thighs touch the floor. Your legs should be spread out wide to create a triangle shape. (iii) Keep your upper body flat and engage your abs by flexing them. Bring your butt up toward the ceiling as you execute your oblique crunches. (iv) If you find it difficult to keep your heels firmly against the floor, you may want to try bending over a bit to move your lower back. If your knees keep continuing to pull into the ground, you're not balanced enough to keep them there.
(i)