Let ⟨ \( a_n \) ⟩ be a sequence such that \( a_0 = 0 \), \( a_1 = \frac{1}{2} \) and \( 2a_{n+2} = 5a_{n+1} - 3a_n \), \( n = 0, 1, 2, 3, \ldots \).Then \( \displaystyle \sum_{k=1}^{100} a_k \) is equal to:
\( 3a_{100} - 100 \)
\( 3a_{99} - 100 \)
\( 3a_{100} + 100 \)
\( 3a_{99} + 100 \)