In the aldol condensation reaction, the product formed when acetaldehyde (CH₃CHO) undergoes a reaction with itself under basic conditions is:
A) Acetic acid (CH₃COOH)
B) 3-Hydroxybutanal (CH₃CH(OH)CH₂CHO)
C) Butanal (CH₃CH₂CH₂CHO)
D) 3-Hydroxybutanoic acid (CH₃CH(OH)CH₂COOH)