345. Additional explosion relief valves are fitted on separate spaces of the crankcase such as gear or chain cases for camshaft or similar drives when the __________.

A. gross volume of such spaces exceeds 21 cubic feet overall volume of the space exceeds 0.6 cubic meters
B. possibility of explosion exists due to the formation of volatile gases
C. unit is operating in extreme overload conditions
D. overall volume of the space exceeds 0.6 cubic meters