Best way to finance a deal?

[Account Closed]

Question:

I have a paid off personal residence worth 800k+

We want to get into real estate investing and we're looking at multifamily properties.  If I find one for 400k would it be better to:

A) Mortgage my own house for 400k and buy it with cash 

B) Mortgage my house for 100k and mortgage the property for 300k.

C) Sell stock investments of 100k and mortgage the property for 300k.

The problem I see with A is I can't really do a 2nd deal like that. C creates a taxable event and I'd owe cap gains right away.   B is the least amount of pain but I don't know that banks actually let you do that.

If any of these are good or bad for reasons I haven't said please share your thoughts!.Thank you!