Ranking of safest type of wallets

Dear Blockgeeks and community,
I am stucked with this question in Bitcoin 101, can not figure out the right answer. Can somebody give me a hand on this and explain why for me please?. Thank you so so much
Arrange the following wallet types from least secure to most secure.
1. Exchange wallet

2. SPV wallet

3. Bitcoin core wallet

4. Hardware wallet.
Thank you so much

Crystal