Correct Answer: ka da sa

Solution : Given:
1. we are going ⇒ ca da ga
2. you are happy ⇒ sa ga ta
3. she is going ⇒ ma ra ca
4. you were ⇒ ta ka

On, comparing all the coded sentences, we find that –
In sentences 1 and 2, are is a common word, and ga is a common code.
In sentences 2 and 4, you is a common word, and ta is a common code.
In sentences 1 and 3, going is a common word, and ca is a common code.
The remaining words and codes in the given sentences are we, were, and happy, and da, ka, and sa .
Finally, are → ga ; you→ta ; going→ca ; we→da ; were→ka ; happy→da

So, we were happy will be coded as ka da sa . Hence, the second option is correct.