Correct Answer: bi

Solution : Given:
1. Shym Studies English in Purna ⇒ pi ji ti fi qi
2. Her sister lives in Mumbai ⇒ mi hi ji ki ni
3. Rama Studies Chemistry ⇒ di li pi
4. Sister Studies English and Chemistry ⇒ bi ki pi di fi

By comparing all the four coded sentences, we find that –
In sentences 1 and 2, in and ji are common.
In sentences 1 and 4, English and fi are common.
In sentences 1, 3 and 4, Studies and pi are common.
​In sentences 2 and 4, Sister and ki are common.
In sentences 3 and 4, Chemistry and di are common.
The remaining words and code in sentence 1 are Shym/Purna and ti/qi ; in sentence 2 are Her/lives and mi/ni ; in sentence 3 are Rama and li ; in sentence 4 are and and bi.
Finally, in ⇒ ji; English ⇒ fi; Studies ⇒ pi; Chemistry ⇒ di; Shym/Purna ⇒ ti/qi; Her/lives ⇒ mi/ni; Rama ⇒ li; and ⇒ bi

So, and will be coded as bi. Hence, the second option is correct.