1. 'call out' means to summon to deal with an emergency or a special work at an unusual time. Hence, 'to call out a doctor’ is correct, 2. ‘Stands in for’ means 'acts as a substitute of'. Hence, 'Stands in for a colleague’ i.e. 'proxy a colleague is correct. 3 'Send down’ means to dispatch somebody to some place or a lower level. Hence, 'Send down a criminal' seems appropriate. 4. 'Send off a footballer’ is also appropriate. Hence, option *b' is the best answer.