Which is a simple sentence?

1. Given the time of day,we were lucky
to find a taxi.
2. Shelia used the lawnmower and Jacob
drove the tractor.
3. Eventually she will.
4. Jennifer and Brian gave money to the
orphanage.

Would number 4 be an example of a
simple sentence?

There are three simple sentences among these four. Number 4 is one of them; which are the other two?

A simple sentence contains only one independent clause, although it can have various modifiers and phrases in it, too.

=)

1 and 2-
but this is where I AM CONFUSED BECAUSE
THERE ARE THREE AND I CAN ONLY CHOOSE ONE

Independent Clause

An independent clause is a group of words that contains a subject and verb and expresses a complete thought. An independent clause is a sentence.

Jim studied in the Sweet Shop for his chemistry quiz.

I don't know which one to tell you to choose. You might speak to your teacher and point out the following:

1. Given the time of day, we were lucky to find a taxi. SIMPLE SENTENCE: one independent clause, two phrases
Given the time of day = participial phrase, not a clause
we were lucky = main subject and predicate
to find a taxi = infinitive phrase

2. Shelia used the lawnmower and Jacob drove the tractor. COMPOUND SENTENCE: two independent clauses
Shelia used the lawnmower = one independent clause
Jacob drove the tractor = second independent clause

3. Eventually she will. SIMPLE SENTENCE: one independent clause
Eventually = adverb
she = subject
will = verb

4. Jennifer and Brian gave money to the orphanage. SIMPLE SENTENCE: one independent clause with a compound subject
Jennifer Brian = compound subject
gave = verb
money = direct object
to the orphanage = prepositional phrase

=)

I apologize for the confusion. You're right, there are three simple sentences among the four options. The other two simple sentences are:

1. Given the time of day, we were lucky to find a taxi.
This sentence has one independent clause: "we were lucky to find a taxi." The phrases "given the time of day" and "to find a taxi" are modifiers within the sentence.

3. Eventually she will.
This sentence also has one independent clause: "she will." The word "eventually" is an adverb modifying the verb "will."

So, in total, there are three simple sentences: 1, 3, and 4.