Multi-select problem: How does the next paragraph end?

How to make yourself cough
Breathe in sharply and close your throat.
Changing the way you breathe in and out, combined with restricting your airflow, can induce a cough. Take in a deep, sharp breath to dry out your mouth and throat.

Select from: a). If the feeling lasts all of a sudden, though, stop doing so immediately and take a breath before proceeding. If a cough persists, you may have another air allergy, such as vomiting or measles.; b). Closing your airways forces air to dilate and expand. As you inhale, let your airways become more developed to better control airflow.; c). Tighten your throat and try to exhale. Tighten your stomach and push air out while keeping your throat restricted.; d). Make sure to exhale air from your nose, rather than from your mouth, as this prevents the mucus from escaping. This will also help to clear your airways.;
c).