The most accurate choice from the options provided is:
4. the coral is susceptible to starvation
After coral is bleached, it loses its symbiotic algae (zooxanthellae) due to stressors like temperature rise, pollution, or other environmental changes. Without these algae, which provide the coral with essential nutrients and energy through photosynthesis, the coral becomes susceptible to starvation and can ultimately lead to its death if conditions do not improve.