To solve this problem, we need to understand the typical dental development in children.$\newline$A two-year-old child typically has a set of primary teeth, also known as deciduous or milk teeth.$\newline$Let's analyze the composition of these primary teeth:$\newline \bullet$A full set of primary teeth consists of 20 teeth.$\newline \bullet$These include:$\newline$ - 4 central incisors (2 upper, 2 lower)$\newline$ - 4 lateral incisors (2 upper, 2 lower)$\newline$ - 4 canines (2 upper, 2 lower)$\newline$ - 8 molars (4 upper, 4 lower)$\newline$Primary teeth do not include pre-molars.$\newline$Pre-molars are part of the permanent dentition and typically appear later, around the age of 10-12 years.$\newline$Therefore, the teeth absent in a two-year-old child are pre-molars.$\newline$This corresponds to Option 2.