Harmonizing melody exercise question with specific parameters

Question

I'm reading the book Harmony for the computer musician and there's an exercise where you need to harmonize 3 notes of a melody in D major, parameters are:

• you must use the same note length as the upper voices
• root position triads only
• triads are I - V - I
• 4 voices
• Avoid consecutive 5ths and octaves
• Have the leading note of the dominant triad rise up to the tonic

He proposes 2 solutions to the problem which are in the image below, one by choosing to not use the leading note of the dominant to rise up to the tonic and another one by using only 3 voices on the third chord.

I came to another solution but I'm guessing it's wrong but I can't figure out why it's wrong. Here's my solution:

Answer 1

The answer you have given has parallel fifths in the bottom two voices between the last two chords. To be more specific, the bass (bottom voice) plays D-A-D while the tenor (second from bottom) plays D-E-A. It is the interval A-E in the second chord, moving to D-A in the last, that gives the parallel fifths.

Answer 2

In addition to the parallel fifths that @Reina pointed out, your solution also breaks the sixth rule since it does not resolve (or rise) the leading tone of the dominant (C#) up to the tonic root (D) as it should, but instead drops a fifth to the third of the tonic (C#-F#).