Answer:
A). His heart that trembles at the beam/ Of her soul-searching eyes.
Step-by-step explanation:
Mood is defined as the atmosphere that the author creates in his work using specific words and descriptions in order to evoke a particular emotional state or feeling among the readers. In this question, the first quotation i.e. 'his heart...eyes' displays an affectionate mood as the descriptions like 'his heart trembles' and 'of her soul-searching eyes' signifies that there is a love and devotion towards each other. Thus, option A is the correct answer.