No banana is a mango. No fruit may be banana. Some bananas may be guavas.
All mangoes are guavas (A) + No guava is a banana (E) ⇒ No mango is a banana (E) ⇒ Conversion ⇒ No banana is a mango (E). Some fruits are mangoes (I) + All mangoes are guavas (A) ⇒ Some fruits are guavas (I) + No guava is a banana (E) ⇒ Some fruits are not bananas (O) ⇒ [Probable conclusion] ⇒ No fruit may be bananas. No guava is a banana (E) ⇒ Conversion ⇒ No banana is a guava ⇒ Some bananas are not guavas (O) ⇒ [Probable conclusion] ⇒ Some bananas may be guavas (I). Hence, option 2 is correct.