Examine Statement I

Statement I says: The electronegativity of group 14 elements from $\mathrm{Si}$ to $\mathrm{Pb}$ gradually decreases.

Group 14 elements are: $\mathrm{C,\ Si,\ Ge,\ Sn,\ Pb}$

Considering from $\mathrm{Si}$ to $\mathrm{Pb}$, the electronegativity values do not decrease gradually in a regular manner.

Approximate Pauling electronegativities are: $\mathrm{Si} \approx 1.90,\quad Ge \approx 2.01,\quad Sn \approx 1.96,\quad Pb \approx 2.33$

So the trend is not a steady decrease:

• $\mathrm{Si} \to Ge$: increases
• $\mathrm{Ge} \to Sn$: decreases slightly
• $\mathrm{Sn} \to Pb$: increases

Therefore, Statement I is false.

Examine Statement II

Statement II says: Group 14 contains non-metallic, metallic, as well as metalloid elements.

Check the members:

• $\mathrm{C}$: non-metal
• $\mathrm{Si,\ Ge}$: metalloids
• $\mathrm{Sn,\ Pb}$: metals

Hence, group 14 indeed contains:

• non-metals,
• metalloids,
• metals.

Therefore, Statement II is true.

Match with options

• Statement I: False
• Statement II: True

So the correct option is: $\boxed{\text{A}}$

Comparison with stored answer

Stored correct answer: A

My derived answer also is A, so they agree.