Arrange the sentences A, B, C and D in a proper sequence so as to make a coherent paragraph.

A. Chemists mostly don't stock it: only a few government hospitals do but in limited quantities.

B. Delhi's building boom is creating a bizarre problem: snakes are increasingly biting people as they emerge from their disturbed underground homes.

C. There isn't enough anti-snake serum, largely because there is no centralised agency that distributes the product.

D. If things don't improve, more people could face paralysis, and even death.