Switching operation modes in vi

Question:
Identify the wrong statement below while switching operation modes in the vi editor:

1. Press ESC to switch to command mode from insert or last line mode
2. Type lower case i to switch between command mode to insert mode
3. Press capital letter T to switch to insert mode from command mode
4. Press colon(:) to switch between command mode to last line mode

Answer:
C - is the correct answer. We can use i, not T, to switch into insert mode from command mode