The question basically asks ....

IS

lal < 0 ??

or a < 0 & a > 0 ......Does the value of a >0 & a <0 .....

Statement : 1 says ......

\sqrt{{a}} / l{b^3}l > 0

or

\sqrt{{a}}> 0

or a > 0 ... Clearly Insufficient as it doesn't tell us if a< 0 also......Therefore, Insufficient.

Statement :: 2 ... Similar to statement it just tells us one part ... i.e;

as Given ...

ab^4 < 0 ... or a <0 .... Clearly, Insufficient.

1+2 ...... gives us that a<0 & a > 0 ..... Therefore, Sufficient.......

Hence, C ................. Hope it Helps !!

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