Melting and boiling points of some substances are listed in the given table :
Fill in the blanks by choosing an appropriate option. The substances which are liquid at – 185°C are __p__ and __q__ and the substance which is a liquid over the largest range of temperature is __r__ .
--------p--------q----------r
AII--------III--------IV
BI---------II--------III
CI---------IV--------IV
DI---------IV--------I
ans should be c