A 6-day old neonate presented to NICU with respiratory depression, poor feeding and persistent occurrence of seizures. The child was born at 39 weeks gestation by spontaneous vaginal delivery to healthy parents O/E: - High forehead with unslanting palpebral fissures Hypoplastic supraorbital ridges Epicanthal folds. Depressed nasal bridge with long philtrum Hearing loss Liver dysfunction, polycystic kidneys and patent ductus aeriosus were also present MRI of the brain. Which of the following entity will be found to be increased in the serum of the baby: -