Does a blocked person get a read receipt when I read an unread message they sent before being blocked?

Here's the chronology:

1. Someone I meant to block sends me an iMessage. Blocked person likely receives a "delivered" receipt at that moment.
2. i DO NOT read the iMessage. The "unread" dot continues to display
3. I go to my contacts and block the person
4. i I do several other tasks over several hours. The iMessage remains instead this whole time and the author remains blocked.
5. I accidentally click on the unread message, rendering it to "read" status
6. Does the blocked person from whom I received the iMessage get to see a "read" receipt at that time?

I figure either a) receipts are really messages, and since the person is blocked from sending me any new messages maybe they don't get any messages I send either, so they do not get the receipt (yay)

-or-

b) receipts are not really messages but since the person is blocked from sending me new messages the sensor for receipts is shut off even for previously sent messages (yay)

-or-

c) blocking a person only blocks things coming FROM them TO me, so my read receipt is able to travel the other direction (to them) unimpeded. (boo)