Which is a complex sentence?

the technician installed my hard drive and turned on my computer.

my computer is lightweight, powerful, and portable.

both computers are powerful, but this one is less expensive.

after you install the security software, your computer will run smoothly.

the fourth one because it has a dependent clause and an independent clause

D) After you install the security software, your computer will run smoothly

Explanation:

Trust me I'm great with computers. ;)

read this passage from the crisis. what rationale is paine using for going to war with great britain? my own line of reasoning is to myself as straight and clear as a ray of light. not all the treasures of the world, so far as i believe, could have induced me to support an offensive war, for i think it murder; but if a thief breaks into my house, burns and destroys my property, and kills or threatens to kill me, or those that are in it, and to "bind me in all cases whatsoever" to his absolute will, am i to suffer it? what signifies it to me, whether he who does it is a king or a common man; my countryman or not my countryman; whether it be done by an individual villain, or an army of them? if we reason to the root of things we shall find no difference; neither can any just cause be assigned why we should punish in the one case and pardon in the other.

it is waged war against an army of countrymen

it would lead to independence from britain

it would be an offensive war

it would be a defensive war