With no explanation, label text_A→text_B with either "DON'T KNOW", "NO" or "YES".
text_A: An audiotape allegedly featuring the voice of bin Laden surfaced on the Internet and addresses the flooding in Pakistan. The 11-minute tape, posted on militant websites Friday, focused on how to prevent relief efforts and what can be done to encourage future natural disasters. In the recording, bin Laden reportedly urges a change in how governments execute relief work and calls for the creation of a group to study Muslim regions located near rivers and low-lying areas. He also calls for a greater investment in agriculture. The U.S.-based SITE Intelligence Group, which monitors jihadi forums, says the latest message is heard in a video featuring a photograph of bin Laden superimposed over images of aid distribution.
text_B: Is it likely that relief groups tightened their security after the Bin Laden video surfaced online?
YES.