哈哈~~大家帮帮忙，为什么答案是D不是C?

4. A typical value for the numeric variable SiteNum is 12.3. Which statement
correctly converts the values of SiteNum to character values when creating the
variable Location?
a. Location=dept||'/'||input(sitenum,3.1);
b. Location=dept||'/'||input(sitenum,4.1);
c. Location=dept||'/'||put(sitenum,3.1);
d. Location=dept||'/'||put(sitenum,4.1);