The correct answer is Timothy Leary.
He used this phrase to encourage people to actively participate in the countercultural movement, which he was a part of.
"Turn on" meant to engage the brain; "tune in" meant to tune into the natural world; and "drop out" meant disengaging from the confines of society. As time went on, this phrase became more about doing drugs than about the actions Leary intended.
I would say A. Leonardo da Vinci invented both the self-propelled vehicle and the tank.
You should always let them have a say and think and accept their anwsers
