To solve this problem, we need to identify the characteristic that Hemichordates share with Chordates.$\newline$Let's analyze each option:$\newline \bullet$Option 1: Ventral tubular nerve cord.$\newline$ - Chordates typically have a dorsal tubular nerve cord, not ventral.$\newline$ - Hemichordates have a nerve cord, but it is not homologous to the chordate nerve cord.$\newline$ - Therefore, this is not a shared characteristic.$\newline \bullet$Option 2: Pharynx with gill slits.$\newline$ - Both Hemichordates and Chordates possess pharyngeal gill slits at some stage of their life cycle.$\newline$ - This is a significant shared feature between the two groups.$\newline \bullet$Option 3: Pharynx without gill slits.$\newline$ - This is incorrect as both groups have pharyngeal gill slits.$\newline \bullet$Option 4: Absence of notochord.$\newline$ - Chordates are defined by the presence of a notochord at some stage.$\newline$ - Hemichordates do not have a true notochord, but this absence is not a shared characteristic.$\newline$Therefore, the correct answer is Option 2: Pharynx with gill slits, which is the characteristic shared by both Hemichordates and Chordates.