$12.$ In the following Received: email header, what does the IP address $64\mathrm{.}191\mathrm{.}152\mathrm{.}28$ show us$?$

Received: from benjamin.hostguardian.com $([64\mathrm{.}191\mathrm{.}152\mathrm{.}28]$:$56279)$

by controller.askgar.com with esmtps $($TLSv$1$:RC$4-$SHA:$128)$

$($Exim $4\mathrm{.}84)$

$($envelope$-$from $)$

id $1$bQglF$-0001$kU$-$PV

for gar@askgar.com; Fri, $22$ Jul $201615$:$09$:$30-0500$

Group of answer choices

a$.$ The website advertised in the email message

b$.$ The IP Address of the mailserver

c$.$ The address of the computer reading the email

d$.$ The IP address of the sender$$s computer