Carbon (C) is most likely to form covalent bonds with selenium (Se).
Here's a brief explanation for each option:
- Beryllium (Be): This is a metal that typically forms ionic bonds rather than covalent bonds.
- Krypton (Kr): This is a noble gas, which has a full valence shell and is generally unreactive, meaning it does not typically form covalent bonds.
- Sodium (Na): This is also a metal and tends to form ionic bonds, especially with nonmetals.
- Selenium (Se): This is a nonmetal that can share electrons with carbon, leading to covalent bonding.
Therefore, selenium is the correct answer as it can form covalent bonds with carbon.