CCNA question on ISO model

One of my customer has asked me about the two following questions:

The process of HTTP asking TCP to send some data and make sure that it is received correctly is an example of what a) Same-layer interaction, b) Adjacent Layer interaction, c) The OSI model, d) All of the above.

Doest adjacent layer interaction means that that HTTP application layer 7 would be right under the TCP transport layer 4 which does not seems to be case since application 6 & 5 are those who are directly below application 4. Why OSI model can't be the answer?

The process of TCP on one computer marking a segment as segment 1, and the receiving computer then acknowledging the receipt of segment 1, is an example of what?

a) Data encapsulation
b) Same layer interaction
c) Adjacent Layer encapsulation
d) The OSI model
e) None of the above

Does this question refers to the definition of TCP (transport layer 4) to provide reliable communication using acknowledgement.

b>My answer
Question 1 - the confusion comes because the TCP/IP model does not map onto the OSI model.

The OSI model as you say has 7 layers so HTTP is at the application layer which then goes to the presentation layer then to the transport layer.

The TCP/IP layer only really has 4 layers - physical/network/transport/application. So with the TCP/IP model b) could ideed be the right answer whereas with OSI strictly speaking it wouldn't.

Question 2 - i would say same layer interaction myself.

Trouble with these sort of questions is different people read things differently and even when the right answer is known there is still scope for disagreement.