Read the following passage and answer next five questions by choosing the correct options:

On my animal-collecting trips for zoos to various parts of the world, I have had to 'mother' quite a number of baby animals, and I have always found it a most nerve-racking task. The first real attempt I made at being a foster-mother was to four baby hedgehogs. The female hedgehog is a very good mother. She constructs an underground nursery for her young: a circular chamber about 30 centimetres below ground-level, lined with a thick layer of dry leaves. Here she gives birth to her babies which are blind and helpless. They are covered with a thick coating of spikes, but these are white and soft, as though made of rubber. They gradually harden and turn brown when the babies are a few weeks old. When they are old enough to leave the nursery the mother leads them out and shows them how to hunt for food; they walk in line, the tail of one held in the mouth of the baby behind. The baby at the head of the column holds tight to mother's tail with grim determination, and they move through the twilit hedgerows like a strange prickly centipede.

To a mother hedgehog the rearing of her babies seems to present no problems. But when I was suddenly presented with four blind, white, rubbery-spiked babies to rear, I was not so sure. We were living in Greece at the time, and the nest, which was about the size of a football and made of oak leaves, had been dug up by a farmer working in his fields. My first job was to feed the babies but an ordinary baby's feeding-bottle was much too large for their tiny mouths. Luckily, a friend's young daughter had a doll's feeding-bottle, and I managed to persuade her to part with it. After a time the hedgehogs took to this and thrived on a diet of diluted cow's milk.

The mother teaches the young ones to hunt for food when they

are old enough to leave their nursery

The correct answer is Option (2) - are old enough to leave their nursery