A prepositional phrase beings with a preposition
Here are some examples of the most basic prepositional phrase:
•At home
At = preposition; home = noun.
•In time
In = preposition; time = noun.
•From Richie
From = preposition; Richie = noun.
•With me
With = preposition; me = pronoun.
•By singing
By = preposition; singing = gerund.
•About what we need
About = preposition; what we need = noun clause.
Most prepositional phrases are longer, like these:
•From my grandmother
From = preposition; my = modifier; grandmother = noun.
•Under the warm blanket
Under = preposition; the, warm = modifiers; blanket = noun.
•In the weedy, overgrown garden
In = preposition; the, weedy, overgrown = modifiers; garden = noun.
•Along the busy, six-lane highway
Along = preposition; the, busy, six-lane = modifiers; highway = noun.
•Without excessively worrying
Without = preposition; excessively = modifier; worrying = gerund.
("Although " is a conjunction not a preposition)
A preposition describes a relationship between other words in a sentence. The only sentence containing a preposition is D. The preposition "With" connects "the proper help" to "complete the project".