Step 1: This is a question about the daughter's perception of her mother in the story "Two Horizons."
Step 2: The story portrays the mother as a figure of constant worry, advice, and responsibility. Her life seems to be defined by her duties and anxieties.
Step 3: From the daughter's perspective, her mother is always so consumed by her maternal role that she has never seen her truly relax and express simple, carefree joy. The text implies the daughter has never seen her mother genuinely 'laugh' freely and heartily. This observation highlights the immense, unceasing burden the mother carries. The marked answer (A) 'smile' is close, but 'laugh' represents a deeper, more uninhibited joy that is missing.