Illegal pream-token in tabular

Question

I'm having trouble constructing a tabular environment and compiling it with pdflatex. Here's what I'm trying to do:

\documentclass{article}
\usepackage[pdftex]{graphicx}
\usepackage{caption,tabularx,booktabs}
\begin{document}
\begin{minipage}{\linewidth}
\centering
\captionof{table}{Left side FBD} \label{tab:title2}
\begin{tabular}{ C C }\toprule[1.5pt]
\bf X & \b
f Y \\\midrule
$0$ & $-F_g$\\
$F_t \sin \theta$ & $F_t \cos \theta$\\
$-F_e$ & $0$\\
\bottomrule[1.25pt]
$0$ & $0$\\
\end{tabular}
\end{minipage}
\end{document}

However, I then get the following error:

! Package array Error:  Illegal pream-token (C): `c' used.

See the array package documentation for explanation.
Type  H <return>  for immediate help.
 ...

l.8 \begin{tabular}{ C C }
                          \toprule[1.5pt]

! Package array Error:  Illegal pream-token (C): `c' used.

I've tried giving each C and argument as I've seen in other source code (I'm still not certain exactly what that argument is for) I get another error message. When I replace C with C{.85in} I now get:

! Package array Error:  Illegal pream-token (C): `c' used.

See the array package documentation for explanation.
Type  H <return>  for immediate help.
 ...

l.8 \begin{tabular}{ C{.85in} C{.85in} }
                                        \toprule[1.5pt]

! Package array Error:  Illegal pream-token (.85in): `c' used.

Does anyone know what I'm doing wrong with my tabular? Thanks in advance!

Answer 1

here is the fixed MWE:

\documentclass{article}
\usepackage[pdftex]{graphicx}
\usepackage{caption,tabularx,booktabs}
\begin{document}
\begin{minipage}{\linewidth}
\centering
\captionof{table}{Left side FBD} \label{tab:title2}
\begin{tabular}{ c c }\toprule[1.5pt]
\bf X & \b
f Y \\\midrule
$0$ & $-F_g$\\
$F_t \sin \theta$ & $F_t \cos \theta$\\
$-F_e$ & $0$\\
\bottomrule[1.25pt]
$0$ & $0$\\
\end{tabular}
\end{minipage}
\end{document}

C should be replaced with c