True statement about the drug of Administration is

1)100%. bioavailability is seen in case of IV route. 2)sterile technique is needed in case of I.V. and I.M. administration. 3)Irritation and loal tissue necrosis is seen in case of imetable routes like intramuscular or s.c. route. 4)In inhalational route, absorption of drugs takes place.from vast suaces of alveoli-so bioavailability is high and action is very rapid. Ref-KDT 6/e p91