This time last week I was staying at home when I was called to attend the meeting.
A.
This time /last week/ I was staying at home when /I was called/ to attend the meeting.
B.
This time last week/ I was staying at home/ when I was called/ to attend the meeting.
C.
This time last week/ I was staying/ at home/ when I was called/ to attend the meeting.
D.
This time last week/ I was staying at home/ when I was called to/ attend the meeting.