The line that indicates that the speaker's wrath increased over time is: Option 3: "And it grew both day and night."

This line suggests that the speaker's wrath intensified continuously, growing day and night, until it reached a point where it bore fruit in the form of an "apple bright."

Let's examine other options in detail:

Option 1: "Night & morning with my tears" Explanation: This line describes the speaker's actions of nurturing their wrath with tears both at night and in the morning. While it suggests the speaker's emotional investment in their anger, it doesn't explicitly indicate the growth of the wrath over time. Instead, it emphasizes the emotional intensity of the speaker's feelings.

Option 2: "I was angry with my foe" Explanation: This line simply introduces the speaker's anger towards their foe. It doesn't provide any indication of the progression or growth of the wrath over time.

Option 3: "And it grew both day and night" Explanation: This line directly addresses the growth of the speaker's wrath. It emphasizes that the anger intensifies continuously, day and night, until it reaches a point where it "bears fruit." This option explicitly captures the progression of the speaker's wrath over time, making it the correct choice.

Option 4: "Till it bore an apple bright" Explanation: This line signifies the culmination or manifestation of the speaker's wrath, rather than its growth over time. While it marks the outcome of the anger, it doesn't explicitly highlight the process of the anger's escalation.