Consider the following grammar and the semantic actions to support that inherited type declaration attributes. Let $X_1, X_2, X_3, X_4, X_5$, and $X_6$ be the placeholders for the non-terminals $D, T, L$ or $L_1$ in the following table:

$$\begin{array}{|l|l|} \hline \text{Production rule} & \text{Semantic action} \\ \hline D \rightarrow T L & X_1.\text{type} = X_2.\text{type} \\ \hline T \rightarrow \text{int} & T.\text{type} = \text{int} \\ \hline T \rightarrow \text{float} & T.\text{type} = \text{float} \\ \hline

L \rightarrow L_1, id & X_3.\text{type}= X_4.\text{type} \\

&\text{addType}(id. \text{entry}, X_5.\text{type})\\ \hline

L \rightarrow id & \text{addType}(id. \text{entry}, X_6, \text{type}) \\ \hline \end{array}$$

Which one of the following are appropriate choices for $X_1, X_2, X_3$ and $X_4$?

- $X_1=L, \: X_2=T, \: X_3=L_1, \: X_4 = L$
- $X_1=T, \: X_2=L, \: X_3=L_1, \: X_4 = T$
- $X_1=L, \: X_2=L, \: X_3=L_1, \: X_4 = T$
- $X_1=T, \: X_2=L, \: X_3=T, \: X_4 = L_1$