So my opinion is Guinea pigs.
1	So	so	ADV	RB	_	6	advmod	6:advmod	_
2	my	my	PRON	PRP$	Case=Gen|Number=Sing|Person=1|Poss=Yes|PronType=Prs	3	nmod:poss	3:nmod:poss	_
3	opinion	opinion	NOUN	NN	Number=Sing	6	nsubj	6:nsubj	_
4	is	be	AUX	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	6	cop	6:cop	_
5	Guinea	guinea	NOUN	NN	Number=Sing	6	compound	6:compound	_
6	pigs	pig	NOUN	NNS	Number=Plur	0	root	0:root	SpaceAfter=No
7	.	.	PUNCT	.	_	6	punct	6:punct	_
