In this poem, what is the significance of the poet’s comparison of love to "childhood’s faith"?

Sonnet 43
by Elizabeth Barrett Browning

How do I love thee? Let me count the ways.
I love thee to the depth and breadth and height
My soul can reach, when feeling out of sight
For the ends of being and ideal grace.
I love thee to the level of every day’s
Most quiet need, by sun and candle-light.
I love thee freely, as men strive for right;
I love thee purely, as they turn from praise.
I love thee with the passion put to use
In my old griefs, and with my childhood’s faith.
I love thee with a love I seemed to lose
With my lost saints. I love thee with the breath,
Smiles, tears, of all my life; and, if God choose,
I shall but love thee better after death.

A.
The speaker expresses longing for her childhood.
B.
The speaker has had faith in love since childhood.
C.
The faith and trust of childhood is the strongest.
D.
Religious faith is strongest in childhood.

Although Elizabeth's adulthood was negatively comapared to her happy an beautiful childhood. You can see in line 10 after the comma, how she compares her love to her childhood's faith, a strong faith, because she was a happy and full of faith person in her childhood. Her love to her husband was as such, because it was faithful, pure and strong. It doesn't have anything to do with religiousness, this is why it isn't D, also, faith in love is not actually the meaning, as she wasn't longing for love in her childhood. She also, although her childhood was beautiful, does not long it for she had her great husband with her, the best part of her life.