Explanation:

- The process of blood clotting is called coagulation.

- Coagulation is your body’s way of stopping bleeding when you get hurt. Tiny cell fragments called platelets and special proteins in your blood team up to form a clot and seal the wound.

- Thrombocytopenia isn’t about clotting—it actually means you don’t have enough platelets in your blood, so it’s harder for clots to form.

- Haemophilia is a disorder where your blood doesn’t clot properly because you’re missing certain clotting factors. People with haemophilia bleed longer after injuries.

- Homophobia has nothing to do with blood at all—it’s a term for prejudice against LGBTQ+ people.

- So, coagulation is the only word here that fits the question.