Flurry of Blows and the Ready action

[Thewms]

(2 Actions)Ready
"You prepare to use an action that will occur outside your turn. Choose a single action you can use and designate a trigger. Your turn then ends. If the trigger you choose occurs before the start of your next turn, you can use the chosen action as a reaction (provided you still meet the requirements to use it).
If you have a multiple attack penalty and your readied action is an attack action, your readied attack takes the multiple attack penalty as if you had spent your readied attack on your turn. This is one of the few times the multiple attack penalty applies when it’s not your turn. For more information about multiple attack penalties, see page 305."

Question
Can a Monk Ready his Flurry of Blows?

I am bit confused on what is an "Action" vs an "Activity" and if there is even a distinction between the two.

[Fuzzy-Wuzzy]

Yes, he can, because it is a single action.

"Activity" is a superset of "action"---anything that takes one or more actions is an activity. Only a single-action activity can be Readied.

[Edge93]

With the caveat that the Monk must have not already used his Flurry of Blows that round. This is a good idea, I hadn't thought of it!