The following table presents the quoted $($i$.$e$.,$ settlement$)$ prices for the respective $3-$year and $10-$year Treasury bond futures. Both bond futures mature in September $2010.$

$3-$year Treasury bond futures

$10-$year Treasury bond futures

$6$ July $2010$

$$92\mathrm{.}65$

$$88\mathrm{.}40$

$13$ July $2010$

$$91\mathrm{.}32$

$$85\mathrm{.}95$

Which of the following statements is most likely to be TRUE?

a$.$

On $6$ July $2010,$ the Treasury yield curve was upward sloping, and appeared to have acquired an even steeper slope on $13$ July $2010.$

b$.$

On $6$ July $2010,$ the Treasury yield curve was downward sloping, and appeared to have transformed into an upward sloping shape on $13$ July $2010.$

c$.$

Between $6$ July $2010$ and $13$ July $2010,$ the bond market appeared to have been spooked by concerns over reports of falling inflation.

d$.$

On $6$ July $2010,$ the Treasury yield curve was upward sloping, and appeared to be less steep $($although still upward sloping$)$ on $13$ July $2010.$