Match the columns:

Column-$I$	Column-$II$	Column-$III$
$(a)$ Common cold	$(1)$ Streptococcus pneumoniae	$(P)$ Inflammation of hands and legs
$(b)$ Pneumonia	$(2)$ Rhinovirus	$(Q)$ Cancer of skin and vessels
$(c)$ $AIDS$	$(3)$ Retrovirus	$(R)$ Disease of nasal congestion
$(d)$ Elephantiasis	$(4)$ Filarial worms	$(S)$ Finger nails turn blue to gray in color

(A) The correct matches are as follows:
$1$. $(a)$ Common cold is caused by $(2)$ Rhinovirus and results in $(R)$ nasal congestion.
$2$. $(b)$ Pneumonia is caused by $(1)$ Streptococcus pneumoniae and results in $(S)$ finger nails turning blue to gray in color.
$3$. $(c)$ $AIDS$ is caused by $(3)$ Retrovirus and can lead to $(Q)$ Kaposi's sarcoma (cancer of skin and vessels).
$4$. $(d)$ Elephantiasis is caused by $(4)$ Filarial worms and results in $(P)$ inflammation of hands and legs.
Therefore,the correct sequence is $(a-2-R), (b-1-S), (c-3-Q), (d-4-P)$.