Option (a) is correct. ‘Bring off' means ‘to carry to a successful conclusion’. Option (b) is correct. ‘Bring in’ means ‘to produce or earn profit’. In option (c) ‘bring out the rear’ is incorrect. It should be 'bring up the rear’ which means ‘to come last or behind’. ‘Bring about’ in option (d) means to ‘to cause to take place’.