A stack of shortwood loaded lengthwise can be secured with one tiedown if `_________`.

A All of these apply.

explanation

One tiedown
A stack can be secured with one tiedown if all logs in the stack less than 3.04 m (10 ft) are:
Blocked in the front by a headboard strong enough to restrain the load or by another stack of logs.
Blocked in the rear by the vehicle's end structure or another stack of logs.