This was marked wrong and its my last attempt please help Wh

This was marked wrong and its my last attempt please help.

Which amino acid has the longest sidechain (don\'t go \'around\' rings; take the shortest path to the endpoint)? Select one: glycine glutamine methionine aspartic acid arginine

Solution

The correct answer is : e.arginine

Reason: Out of all the aminoacids, arginine has the longest chain in R group.