I am so confused with all of this. I am really bad at English, please help and explain, Thank you

Using the following abbreviations, tell how each quoted noun clause is used:
S- Subject, SC- subject complement, DO- direct object of verb, OP-object of preposition.
• The thief confessed "that he had stolen the bricks from the site".
• The fresh air is "what I like best about the farm".
• The bill must be paid by "whoever purchased the lumber".
• "What you say about the Mideast problem" is true.
• "Whatever you tell me" shall remain our secret.

Question

I am so confused with all of this. I am really bad at English, please help and explain, Thank you

Using the following abbreviations, tell how each quoted noun clause is used:
S- Subject, SC- subject complement, DO- direct object of verb, OP-object of preposition.
• The thief confessed "that he had stolen the bricks from the site".
• The fresh air is "what I like best about the farm".
• The bill must be paid by "whoever purchased the lumber".
• "What you say about the Mideast problem" is true.
• "Whatever you tell me" shall remain our secret.

madhu.mukherjee.946 · Answer

i.do
ii.sc
iii.op
iv.s
v.s

jack1 · Answer

agree with most... but I'm 50/50 on:  v. s  ... are u sure it's not SC?