You can add a link in the email to point to SurveyMonkey.
Marketo does not have any native survey capability. See launchpoint.marketo.com for any partners. What I've heard is you have to go to the third party.
You can obtain the integration by going directly to survey monkey, the last time I checked it was running about $5k per year to enable all of the functionality on the SM side.
Additionally, you can take this approach one step further and use the Survey Monkey link structure and Marketo Tokens to prefill some answers (e.g. name and email address) if you so desire.
I work at Survicate, and I'd like to suggest you the alternative to Survey Monkey's questionnaires. Survicate is the all-in-one customer survey software, and it has direct integration with Marketo. It is also the official Marketo's LaunchPoint Partner.
It specializes in micro surveys which are perfect for running at different stages of a buyer's journey. It allows you to run surveys directly on your website (with targeted website surveys) or embed the first question in your emails (for example in Marketo). The answers are sent to your Marketo database in the real-time and saved as lead fields and lead activities.
This is the example of how NPS email surveys look in Marketo: