The reagent among the following that does not reduce an aryl nitro compound to an amine is:

1. H2(excess) / Pt

2. LiAlH4 in ether

3. Fe and HCI

4. Sn and HCI

Hint: Strongest reducing agent didnot use 
Aryl nitro compound can't be converted into amine using LiAlH4 in ether.
When aryl nitro reacts with LiAlH4 in ether then azobenzene is formed as product.
The structure of azobenzene is as follows:
The reactions of aryl ketone with other reagent is as follows:
Hence, option (2) is the choice.