gate forum test

Question

Answer 1

I think the answer should be B.  

The state machine in Option A will accept 111 as an input and C will accept both 11 and 111 as its input. 

Comments

why $B$?

$B$ too will accept $11$ or $111$ see at last of B, there is $(0+1)^{*}$

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@ sourav But you have to accept four preceding symbols which make string other than given right?

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In option B, its of this type
 

X . Y is a Regular Expression corresponding to the language L(X) . L(Y) 
where L(X.Y) = L(X) . L(Y)

The X in option B is (0 + 1(0+1(...))) and Y is (0 +1)*. 
The languages it will accept will contain both X and Y. The "+" is used as union and "." is used for intersection. Both things must be included. 
Here's a link to a good resource.

My explanation is not much clear but I hope these hints might have helped you get an idea about my approach. 

Does it help?

You 

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yes you are right actually i thought of $11$,$111$ as substring