Đáp án:
- \( A(a, 0, 0) \in d_1 \), \( B(1, b, 0) \in d_2 \), \( C(1, 0, c) \in d_3 \).
\( \overrightarrow{AB} = (1 - a, b, 0), \quad \overrightarrow{BC} = (0, -b, c), \quad \overrightarrow{CH} = (2, 2, 1-c), \quad \overrightarrow{AH} = (3 - a, 2, 1). \)
H là trực tâm \( \Delta ABC \Leftrightarrow \begin{cases} H \in \Delta ABC \\ \overrightarrow{CH} \perp \overrightarrow{AB} \\ \overrightarrow{AH} \perp \overrightarrow{BC} \end{cases} \)
\( \Leftrightarrow \begin{cases} [\overrightarrow{AB}, \overrightarrow{BC}] \cdot \overrightarrow{CH} = 0 \\ \overrightarrow{AB} \cdot \overrightarrow{CH} = 0 \\ \overrightarrow{BC} \cdot \overrightarrow{AH} = 0 \end{cases} \Leftrightarrow \begin{cases} 2bc + 2c(a - 1) + (1 - c)b(a - 1) = 0 \\ a = b+1 \\ c = 2b \end{cases}\)
\( \Leftrightarrow \begin{cases} 9b^2 - 2b^3 = 0 \\ a= b+1 \\ c= 2b \end{cases} \Leftrightarrow \begin{cases} b = 0, \, c = 0, \, a = 1 : A \equiv B (\vec{AB} = 0): \text{loại} \\ b = \frac{9}{2}, \, a = \frac{11}{2}, \, c = 9 \end{cases} \)
\( A \left(\frac{11}{2}, 0, 0\right), \, B \left(1, \frac{9}{2}, 0\right), \, C(1, 0, 9). \)
Phương trình mặt phẳng \( \Delta ABC \): \( 2x + 2y + z - 11 = 0 \Rightarrow \boxed{A}\)