Which of the following compounds contains the most electronegative carbon atom marked with an asterisk (*)?

1. ${\mathrm{CH}}_3-{\mathrm{CH}}_2-*{\mathrm{CH}}_2-{\mathrm{CH}}_3$

2. ${\mathrm{CH}}_3-*\mathrm{CH}=\mathrm{CH}-{\mathrm{CH}}_3$

3. ${\mathrm{CH}}_3-{\mathrm{CH}}_2-\mathrm{C}\equiv *\mathrm{CH}$

4. ${\mathrm{CH}}_3-{\mathrm{CH}}_2-\mathrm{CH}=*{\mathrm{CH}}_2$