Voted for Invest in parts.

I'm thinking that this is the option that means diversify your holdings?

I would say that it depends a lot on your overall financial situation, and this question really does not give enough context. In my opinion, if you are already well-diversified outside of crypto, diversification within crypto is less important. (I recognized that's a little controversial, but let's be honest- all non-scam coins are highly correlated!)

If you are comfortable with increasing your crypto exposure, it's better to be focused on just 3-4 coins so that you can keep up with development progress, key milestones, and potential changes to the internal micro-economies of each blockchain.